/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.common.networking;

import net.sf.freecol.common.model.Game;
import net.sf.freecol.common.model.NationSummary;
import net.sf.freecol.common.model.Player;
import net.sf.freecol.server.FreeColServer;
import net.sf.freecol.server.model.ServerPlayer;

import org.w3c.dom.Element;
import org.w3c.dom.NodeList;


/**
 * The message sent when summarizing a nation.
 */
public class GetNationSummaryMessage extends DOMMessage
{

    /** The identifier of the player to summarize. */
    private final String playerId;

    /** The summary. */
    private NationSummary summary;


    /**
     * Create a new <code>GetNationSummaryMessage</code> for the
     * specified player.
     *
     * @param player The <code>Player</code> to summarize.
     */
    public GetNationSummaryMessage( Player player )
    {
        super( getXMLElementTagName( ) );

        playerId = player.getId( );
        summary = null;
    }

    /**
     * Create a new <code>GetNationSummaryMessage</code> from a
     * supplied element.
     *
     * @param element The <code>Element</code> to use to create the message.
     */
    public GetNationSummaryMessage( Element element )
    {
        super( getXMLElementTagName( ) );

        playerId = element.getAttribute( "player" );
        NodeList nodes = element.getChildNodes( );
        summary = ( nodes == null || nodes.getLength( ) != 1 ) ? null
                : new NationSummary( ( Element ) nodes.item( 0 ) );
    }


    // Public interface

    /**
     * Client side helper to get the summary.
     *
     * @return The summary.
     */
    public NationSummary getNationSummary( )
    {
        return summary;
    }


    /**
     * Handle a "getNationSummary"-message.
     *
     * @param server The <code>FreeColServer</code> handling the message.
     * @param connection The <code>Connection</code> message was received on.
     *
     * @return An update containing the nation summaries, or an error
     *     <code>Element</code> on failure.
     */
    public Element handle( FreeColServer server, Connection connection )
    {
        final ServerPlayer serverPlayer = server.getPlayer( connection );
        final Game game = serverPlayer.getGame( );

        Player player = game.getFreeColGameObject( playerId, Player.class );
        if ( player == null )
        {
            return DOMMessage.clientError( "Not a player: " + playerId );
        }
        else if ( player.isIndian( ) && ! serverPlayer.hasContacted( player ) )
        {
            return null;
        }

        // Proceed to get the summary.
        summary = server.getInGameController( )
                .getNationSummary( serverPlayer, player );
        return toXMLElement( );
    }

    /**
     * Convert this GetNationSummaryMessage to XML.
     *
     * @return The XML representation of this message.
     */
    @Override
    public Element toXMLElement( )
    {
        Element result = createMessage( getXMLElementTagName( ),
                                        "player", playerId );
        if ( summary != null )
        {
            result.appendChild( summary.toXMLElement( result.getOwnerDocument( ) ) );
        }
        return result;
    }

    /**
     * The tag name of the root element representing this object.
     *
     * @return "getNationSummary".
     */
    public static String getXMLElementTagName( )
    {
        return "getNationSummary";
    }
}
